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Letters Patent No. 93,808, dated August 17, 1869.

IMPROVEMENT IN HOLLOW AUG-ER.

The schedule referred to in thesenmers Patent and making part of thesame.

'To all whom. 'it may concern Be Ait'known that I, WILLIAM A. CLARK, ofWoodbridge, in the county of N cw Haven, and State of Connecticut, haveinvented a new Improvement in Hollow Angers; and 1 do hereby declare thefollowing, when aken in connection with the accompanying drawings, andthe letters of reference marked thereon, to be a ltoll, clear, and exactdescription of the same, and which Said drawings constitute vpart ofthisspecieation, and represent, .iii- -A Figure 1, a View of thecutting-end;

Figure 2, a side view; and iu Figure 3, a view turned one-fourth aroundfrom This invention relates to an improvement in hollow angers, such asare commonly used for boring round euons, as, for instance, the outerend of carriage- Spokes, the object of the invention being a moreperfeet security of the cutter than has heretofore been done.

The improvement, as here shown, is made in the ad- 'nstable auger forwhich Letters Patent vere granted 0 rue, bearing date June 12, 1860,wheren the two parts, each holding one of the cutters, are adjusted to mfrom each other, so as to retain a parallel position e? the two parts ofthe head.

'lhe invention consists in forming a dovetail groove in the respectivehead, to receive one edge of the cuttex', and combining therewith, uponthe outer edge, a4 dovete-il clamp, in such manner that the cutter isPrmly secured in its position.

To enable others skilled in the art to make and use my invention, I willproceed to describe the saine as 'illustrated in the accompanyingdrawings.

A is one part, and B, the other part, of a cutterhead, the part A beingformed upon a shank, C, and the other part adjustable thereon, so as tobe moved iper from ,the part A, and retained in a parallel posi- {fon byset-screws a, u and the adjusting-screw d.

The cutters D D are both similarly fixed. i

'A groove is formed in the head, as seen atj, iig. 2, into which oneedgeof the cutter ts,

The outer edge of the cutter is bevelled in like manner as the inner,and over this a clamp, E, is. placed, its upper edge of dovetail form,so as to lit over the edge of the cutter, as seen at i, tig. 2.

The said clamp extends down, so' as to clasp under the head, as seen ata, iig. 2; then through the clamp, into the head, a screw, F, is placed,so as to bind the clamp hard downnpon the cutter, the'bevelled edge ofthe clamp serving to draw the cutter down upon its seat. By thisarrangement, the lip n, ou the clamp, takes the principal portion of thestrain, so that the screw F is greatlyrelieved, as the tendency ofthestrain upon the cutter is to throw up the cutter, which, were it not forthe lip fu, would come directly upon the screw.

By this arrangement, the cutters are easily adjusted or removed, bysimply loosening the screw F, and the yutters may be formed in a barfandcutoff at the required length, thu's making the construction of thecutter but a trilling cost.

The advantages of this manner of adjustment over vthe head, slotted toreceive the cutters, as heretofore constructed, are too apparent torequire further statenient inthis description.

Havingr fully described my invention, Vliat I claiin as new and useful,and desire to secure by Letters Patent, is-

In combination with the cutters D, the clamp E, constructed so as tograsp the hea/d of the auger and edge of the cutter, substantially inthe nianner and for the purpose herein set forth.

WM. A. CLARK. Witnesses:

A. J. Tinnltrs, tI. H. SHUnwAv.

